Gregorio Herdoiza

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We present results of dynamical simulations of N f = 2 degenerate Wilson twisted mass quarks at maximal twist in the range of pseudo scalar masses 300 MeV m PS 550 MeV. Reaching such small masses was made possible owing to a recently developed variant of the HMC algorithm. The simulations are performed at one value of the lattice spacing a 0.1 fm. In order(More)
In a recent paper [1] we presented precise lattice QCD results of our Eu-ropean Twisted Mass Collaboration (ETMC). They were obtained by employing two mass-degenerate flavours of twisted mass fermions at maximal twist. In the present paper we give details on our simulations and the computation of physical observables. In particular, we discuss the problem(More)
We present the results of a lattice QCD calculation of the average up-down and strange quark masses and of the light meson pseudoscalar decay constants with N f = 2 dynamical fermions. The simulation is carried out at a single value of the lattice spacing with the twisted mass fermionic action at maximal twist, which guarantees automatic O(a)-improvement of(More)
We present an update of the results for pion mass and pion decay constant as obtained by the ETM collaboration in large scale simulations with maximally twisted mass fermions and two mass degenerate flavours of light quarks. We discuss the continuum, chiral and infinite volume extrapolation of these quantities as well as the extraction of low energy(More)
We review some decays that require knowledge of the decay constants of 0 + heavy-light mesons. We compute the decay constants of P-wave heavy-light mesons from unquenched lattice QCD at a single lattice spacing. For the charm-strange meson we obtain the decay constant: fD s 0 + = 340(110) MeV using our normalisation conventions. We obtain the f static Ps(More)
We apply finite-size recursion techniques based on the Schrödinger functional formalism to determine the renormalization group running of four-fermion operators which appear in the ∆S = 2 effective weak Hamiltonian of the Standard Model. Our calculations are done using O(a) improved Wilson fermions with N f = 2 dynamical flavours. Preliminary results are(More)
We present the results of the first lattice QCD study of the strong coupling g D * Dπ. From our simulations in the quenched approximation, we obtain g D * Dπ = 18.8 ± 2.3 −0.06. Whereas previous theoretical studies gave different predictions, our result favours a large value for g c. It agrees very well with the recent experimental value by CLEO. ˆ g varies(More)